Friday, July 17, 1998 Last modified at 2:27 a.m. on Friday, July 17, 1998

Ancient animal puzzle

Scientists extract DNA from 20,000-year-old dinosaur dung

WASHINGTON (AP) - New from science: a technique to extract DNA from 20,000-year-old dung. It can't be used to create extinct creatures like Hollywood scientists do with DNA in dinosaur movies, but it may solve mysteries about animals now gone forever.

"This is not 'Jurassic Park,"' said Hendrik N. Poinar, a University of Munich researcher. "It's more like 'Poop Park.' "

Poinar, a molecular biologist, led a team that discovered a chemical agent that will extract from ancient dung DNA fragments that come from the animal and from the food it ate.

The researchers, reporting Friday in the journal Science, said the technique has been used on dung from a giant American ground sloth that disappeared from the fossil record about 11,000 years ago. The dung was found in a Gypsum Cave in Nevada and was age dated at about 20,000 years.

The scientists are now using the same technique to search for DNA from manure thought to have come from some of the other 20 species of large animals that disappeared about the time humans first moved into the American continent about 11,000 years ago.

"Paleontologists have reached kind of a dead end in explaining why those animals went extinct," said Poinar. "I think the answer may be in the dung - the genetics of the dung."

Some other scientists said extracting DNA from ancient dung is an important advance in the study of animals gone forever.

Poinar said that the extreme dryness of some caves in Arizona and Nevada preserved excrement for thousands of years, but it is difficult for scientists to determine which animals left the droppings.

With the new technique, he said, researchers will be able to identify the animals through their genetic structure. Cells from the animals' gut are sloughed off into the feces and these cells contain the DNA.

The studies also detect DNA from what they ate and from the parasites that tormented them.